As violence over sharp tuition fee hikes swept across London last night, protesters ambushed the car carrying Prince Charles and his wife Camilla, the Duchess of Cornwall.

Demonstrators spotted the royal couple in their purple Rolls-Royce as they were riding through London’s theater district surrounded by a cordon of motorcycles. A mob of around 50 demonstrators, many wearing full-face balaclavas, managed to shove through their police escort, which included armed royal security guards. They then hurled paint bombs at the car, kicked dents into its doors and smashed its rear window — all the while chanting “off with their heads!” and “Tory scum!”

As part of the security detail, a Jaguar carrying officers tailed the Rolls-Royce. It was so battered and broken by the attack that police decided to use its doors as shields from the storm of projectiles, which included bags of trash, traffic cones, bottles and plastic barriers from road works.

Images broadcast on national television late Thursday night and photographs splashed across the front of British newspapers Friday morning capture Camilla’s horror. Dressed in a green evening gown and a diamond-encrusted emerald necklace, she drops her jaw, gasps and reaches for tuxedo-clad Charles. A rioter holding a metal bar can be seen outside of her window.

A spokeswoman with Clarence House, Charles’ office and official residence, said the pair emerged from the incident unscathed: “We can confirm that their royal highnesses’ car was attacked by the protesters on the way to their engagement at the London Palladium this evening. Both their royal highnesses were unharmed.” And despite the terror written on their faces, Camilla and Charles still attended a pre-Christmas variety show at which they were the guests of honor. Camilla emerged from the theater in seemingly good spirits. “First time for everything,” she said.

But this was no laughing matter: someone could have been killed. Speaking to the Daily Telegraph, security analyst Charles Shoebridge said armed royal protection officers traveling with the couple would have considered opening fire had they perceived a threat to their passengers.

“This is a very serious incident. It ranks amongst the most serious security breaches of the past decade,” he said. “Some of the demonstrators yesterday were carrying petrol, specifically to use in arson attacks. If the can of paint had been a can of petrol, it would have been very different.”

Hours earlier, members of Parliament voted to triple annual tuition fees to £9,000 ($14,200), igniting a wave of discontent. Tens of thousands of students took to the streets and, among other things, set fires in Parliament square, smashed windows at the Treasury, and urinated on a statue of Winston Churchill. Officials have said publicly that the student marches attracted violent anarchists and gangs who came not to protest rising tuition fees, but to damage public buildings and harm the police. By mid-evening, Scotland Yard reported that at least 12 policeman had been injured, six of them seriously.

“Right-minded people, including peaceful protesters who wanted to make their point, will condemn what we saw today,” Sir Paul Stephenson, the chief of London’s Metropolitan police, said Thursday night. Prime Minister David Cameron has described the attack as “shocking and regrettable.”